Steering linkage in wheeled vehicle for steering the vehicle along guide rails

Abstract

A first link member branched into two straight arms at a fixed angle is pivotally supported by the vehicle body at the branching point, and the free end of the first arm is linked with a connecting rod which in turn is connected to a steering arm for a road wheel while the free end of the second arm is pivoted to an end of a straight second link member which is equal to the second arm in length, the other end of which second link member is pivoted to a middle portion of a rod supporting at the ends thereof a pair of guide wheels. The rod is provided with means to move the rod relatively to the vehicle body thereby to retract the guide wheels and rotate the second link member until it forms no angle between the second arm.

What is claimed is: 
     
       1. A steering linkage in a wheeled vehicle having at least a pair of retractable guide wheels other than ordinary road wheels for guiding the vehicle along a guideway provided with curved guide rails, the linkage comprising: a connecting rod connected at one end thereof to a steering arm for steerable road wheels of the vehicle;   a first link member consisting of first and second bars fixed at a first angle with each other at one end of each bar, said first link member being pivoted to a structural member of the vehicle at the branching point of said bars, the extending end of said first bar being pivoted to the extending end of said connecting rod;   a bar-shaped second link member equal to said second bar in length, an end of said second link member being pivoted to the extending end of said second bar; and   a supporting rod supporting movably on each end portion thereof a bracket on which a guide wheel is mounted, said supporting rod being movably connected to a structural member of the vehicle, the other end of said second link member being linked with a middle portion of said supporting rod such that said second link member is rotatable about an axis vertical to the longitudinal axis of said supporting rod; said second link member making a second angle between said second bar when the guide wheels are positioned to roll on the guide rails, said second angle becoming zero when the guide wheels are retracted and said supporting rod is moved toward said first link member.   
     
     
       2. A linkage as claimed in claim 1, wherein said first angle is a right angle. 
     
     
       3. A linkage as claimed in claim 1, wherein said supporting rod is cylindrical and arranged horizontally and laterally of the vehicle, and said each end portion is thread-engaged with a jacket member, said jacket member being pivoted to a third link member rotatably connected to said structural member of the vehicle at a distance from said supporting rod in a direction parallel to the longitudinal axis of the vehicle, said end portions being provided with right-hand threads and left-hand threads, respectively, said linkage further comprising a hollow junction member receiving turnably therein said middle portion of said supporting rod, said other end of said second link member being pivotally mounted on said junction member. 
     
     
       4. A linkage as claimed in claim 3, wherein said supporting rod has an annular flange at said middle portion, and said junction member is provided with a through and stepped bore accommodated to the outer diameters of said rod and said flange such that said supporting rod is turnable on the axis thereof without causing said junction member to turn, said other end of said second link member being pivoted to an exterior surface of said junction member. 
     
     
       5. A linkage as claimed in claim 4, further comprising a turning means to provide a rotatory motive force in either direction and a force-transmitting means to transmit said motive force to said supporting rod, said turning means being mounted on said junction member, said force-transmitting means being arranged such that said supporting rod is turnable on the longitudinal axis thereof in either direction. 
     
     
       6. A linkage as claimed in claim 5, wherein said bracket is pivoted to said jacket member by a common pivot to said third link member. 
     
     
       7. A linkage as claimed in claim 5, wherein said turnable means is an electric motor, and said force-transmitting means is a gear train.